INTRO: Pounded by heavy traffic for 25 years on a busy main line, a trial section of ballastless track survived without maintenance, confirming that the design using prefabricated segments was well suited for high speed lines. Ralf Roman Rossberg reports

’THIS DESIGN offers track stability for decades’, enthuses Peter Wegerer, Project Manager for the Nürnberg - Ingolstadt high speed line. His conviction stems from a quarter-century of operational experience with a trial section of the track that was laid on the adjacent Ingolstadt - München main line.

In 1977 a 450m section of ballastless track using prefabricated segments was installed between Dachau and München-Karlsfeld, together with four other types. No fewer than 500million gross tonnes have passed over the site, and to date no maintenance has been needed, other than to the rails. This prompted DB Netz to choose it for use on Germany’s second line built for operation at 300 km/h.

Since around 2000, DB’s policy has been to install ballastless track on high speed lines. Although capital costs are higher, DB judged that the promise of low or zero maintenance without the need for expensive possessions would be well worthwhile.

Long-term experience

’Although the trials with linked prefabricated slabs began as long ago as 1977, until now no-one has been willing to use it in commercial track as there was no long-term experience’, says Dr Andreas Zachlehner, Head of Ballastless Track Construction in the consortium responsible for building the northern section of the 89 km new line, ARGE Baulos Nord.

A few years ago construction company Max B